Engineering Chikugunya Vaccine Based On The Fusion Of E2ep3 Peptide Into Papaya Mosaic Virus Nanoparticles

Background: Chikugunya (CHIKV) is transmitted by the mosquito vectors Aedes aegypti and Aedes albopictus. The CHIKV disease is characterised by acute symptoms that generally last about a week and are self-limiting. At present, there is no available licensed vaccine or particularly effective drug for human use for any alphaviruses. Owing to this, the research was conducted by designing a fusion of E2EP3 with papaya mosaic virus nanoparticles. Methods and materials: Firstly, recombinant papaya virus particle fused with CHIKV peptide-epitope E2EP3 was designed. Subsequently, the fusion was cloned and expressed in competent cells. After purification of the fusion protein, immunisation assay was carried out in mice and CHIKV-specific IgG antibodies were determined. Following this, in vitro neutralisation, plaque formation assay and indirect immunostaining were performed. Results: From this study, the recombinant vaccines were expressed and purified with the expected size approximately 27–30 kDa. In vivo analysis revealed that the recombinant vaccines were able to induced immune response in mice against CHIKV. The results were further analysed through plaque formation assay, and the infected Vero cells treated with he recombinant vaccines demonstrated no plaque formation. Conclusion: The data showed that levels of neutralising antibodies correlate with a protective immune response, which can accelerate the development accessibility of CHIKV. Therefore we sought to investigate further on the protection efficiency and immunogenicity of engineered papaya mosaic virus nanoparticles fused with peptide-epitope derived from CHIKV E2 protein.